stale-while-revalidate (s-w-r for short) is an HTTP header that defines an extra window of time during which a cache (proxy, user agents) can use a stale asset as long as it revalidates it asynchronously. This improves subsequent page load latencies as stale assets are non longer in the critical path.


Established standard

Status in Chromium

No active development (launch bug)

Consensus & Standardization

  • No public signals
  • No public signals
  • No public signals
  • Positive


Last updated on 2017-03-10